Sound-reproducing machine



- Oct. .18, 1927- J. R. OBRIEN Ei- AL SOUND REPRODUCING MACHINE 2 Sheets-Sheet 1 Filed March 24. 1926 1: vnfdmf 701w 2030'! 03117221.

164 2 Oct. 18,1927. R. OBRIEN ET AL 59 2 S OUND REPRODUCING MACHINE Filed March 24. 1926 2 Sheets-Sheet 2 Patented Oct. 18, 1927.

UNITEDSTATES PATENT OFFICE.

JOHN ROBERT OBRIEN, or NORTH MELBQUBNE, arm wILrnEn REVELL, or MEL; BOUBNE, VICTORIA, AUSTRALIA, assrenons r0 ans/rune enoaen'sanxnn am) GEORGE ALBERT RAVISON, TRADING GI MELBOURNE, AUSTRALIA IN PARTNERSHIP AS BARKER &- RAWSON,

SOUND-BEPRODUGING MACHINE.

Application filed March 24, 1926, Serial No. 97,028, and in Australia May 22, 1925.

This invention relates to talking machines, more particularly to a talking machine wherein the sound waves from the reproducer are caused to pass upwardlyt'rom the delivery end of the tone arm into a sound passageway and thence laterally and for wardly and also preferably downwardly along the latter to the open outer end of the passageway through which the sound is emitted. v,

In a talking machine possessing such features, the revolvable record carrier and the tone arm are located in a compartment formed at one side of, and in substantially the same horizontal plane as the sound passageway or amplifier compartment which is formed or defined by the top and adjacent side and rear walls of the cabinet, a floor or bottom piece and an upstanding partition wall, the latter separating said compartment containing the record carrier and the tone arm from the sound passageway. This construction of the cabinet and formation of the sound passageway has, however, presented difficulties chiefly with regard to the assemblage of the various parts. it hasalso been ascertained that the sound waves entering the sound passageway from the tone arm are liable to impinge against the top of the cabinet and give rise to echoes which hear the clarity of the tonal effect.

The present improvements are the result of investigations which have been made in order to remove the objections before referred to, and according to this invention a suitably shaped amplifier shell of unitary construction is provided which is separate from the cabinet structure and isadapted for-insertion and retention within the amplifier compartment of the cabinet, means being provided at the inner end of said amplifier shell {or connecting it to the upwardly directed delivery end of the tone arm. The amplifier shell is so constructed and shaped that the sound waves from the tone arm are ,caused to follow an upwardly curved path into the amplifier and are thence directed laterally and forwardly; the sound passage provided by the amplifier shell progressively increasing in cross sectional area" from its inner to its outer end and being devoid of abrupt or acute bends. Q Referring to the drawings which form part of this specification Figure 1 is a broken perspective view of the upper part of a sound reproducingmachine embodying the present improvements. Figure 2 is a reduced part sectional side elevation of the machine. v Figure 3 is a horizontal section taken, on the line 3-3 in Figure 2.

lljigure 4 an enlarged view in side elevation of an amplifier shell in accordance with this invention and as seen in the preceding figures. r Figure 5 is a part sectional plan taken appron'imately on the line 55 in Figure 4.

F1gures 6 7 and 8 arei'ragmentary.sections taken on the lines 6-6, 7 -7 a1id88 respectively in Figure 5 and illustrating constructional features of the amplifier. 4

Referring more particularly to Figures 1, 2 and 3 itwill be seen that the rotatable record carrier 11' and the tone arm 12 are located within a compartment 13 which is formed between the top 14 of the cabinet and ahorizontal board or deck 16 disposed a suitable distance beneath the top, and by a vertical partition wall 17 which preferably ext-ends diagonally inwards from one of the corner uprights 18 of the cabinet and is curvedlso as to provide adequate spacefor the record carrier 11 which the wall 17 par tially surrounds. A vertical beading strip 19 may be provided to securely retain oneend portion of the partition wall 17 to the adjacent corner upright 18. The said partition wall 17 may he stepped or cut away near its other end so as to provide an overhanging portion 21, the bottom ofwhichi's closed by a horizontal panel which may be fas-v tened to the rear wall 23 of the cabinet, while the outer end is closedfby a vertical panel 24 secured by 'screwsor the like. 'AC cess is had to the record carrier and tone arm by way of an opening iorn'ied in the adjacent sidewall 27 of the cabinet This opening is normallyclosed by a door 28 adapted to swing'outwardly and downwardly into .a (horizontal position ,7 in which it may (ill be supported by articulated links or a chain as at so that it may serve as a rest for records during changing operations.

According to the invention, the amplifier shell, which is constructed separately from the cabinet structure, is adapted for inser' tion and retention within an amplifier compartment 29 which is defined by the top 14, the deck 16, the partition wall 17, the rear wall 23 and the side wall 25 of the cabinet structure. Referring more particularly to Figs. 4 to 8, it will be seen that the amplifier shell has a top 31, a bottom 32 opposite upstanding walls indicated in general by the reference numerals 33 and 34, and a closure 36 at its inner extremity, all of which portions may be composed of wood Or any other suitable material and adapted to form a: unit. The amplifier shell may, however. be moulded or cast from a fibrous or other suitable material or composition, in which instance, the portions before mentioned will be integral one with another. lVhere constructed of wood or like material the upstanding walls 33, 34 may be secured to the top 31 and the bottom 32 by tacks or the like indicated at 38 and, if desired, the joints so formed may be reinforced and rendered sound proof by strips 39 of suitable fabric or like material which are fastened by adhesive or cement so as to cover the adjacent edge portions of the various parts of the amplifier shell.

Viewed in plan the amplifier shell may be said to have a relatively narrow sidewise or laterally extending inner portion A at the inner extremity of which provision is made for connection to the tone arm 12, as hereinafter described, and an intermediate curved portion B integrally uniting said inner portion A with an outer flared portion C which extends forwardly from said curved portion and is adapted to register with an opening in the front of the cab net through which the sound is emitted. The inner portion A which is located within the reduced portion of the amplifier compartmentformed by said overhanging wall 21. is bounded at its rear side by wall 33 which extends substantially parallel to the rear wall 23 of the cabinet and at its front side by wall 34, which extends substantially parallel with the overhanging wall 21. The intermediate curved portion B of the amplifier shell, has a major bend 33 and a minor bend 34. The major bend 33 merges into a straight outer portion 33 extending parallel to the side wall 25 of the cabinet.

the minor bend 34 IIIGILlH into an outer curved or inclined portion 34 which extends forwardly and laterally therefrom in close proximity to the similarly curved or inclined portion of the partition wall 17 to impart the requisite flare to the shell.

The top 31 of the amplifier shell is substantially horizontal throughout and the bottom 32 may be horizontal from the inner end thereof to the said intermediate curved portion B from which latter the bottom 32 may be progressively declined to its outer end to register with the bottom edge of the sound outlet opening 35 of the cabinet. The bottom of the shell may comprise two sections, namel an innersection 32 which may be relatively thick and extend from the inner end to the intermediate curved portion B, and an outer section 32 which may be relatively thin and extend from said intermediate curved portion B to the open outer end of the shell. The, said inner section 32 may be recessed to accommodate the adjacent portion of the outer section 32 and the sections are suitably fastened together to provide a flush joint as at 32. "The inner portion A of the amplifier shell may have affixed thereto a foot or supporting plate 41 provided with laterally projecting portions 42 whereby the shell may be attached by screws or the like 43 to the aforesaid horizontal panel 122 disposed beneath the overhanging portion 21 of the partition wall 17 before referred to, and to which panel 22 the tone arm 12 is suitably attached. The foot 41 may have a central raised portion 44 which is disposed between the upstanding walls 33. 34 of the shell, and nails. tacks. or the like may be driven through said walls into the raised portion 44. as indicated at 45, (Fig. 8), to hold the foot 41 in proper position. Or. instead of said central raised portion 44, a separate insert piece may be disposed between the foot 41 and the am plifier bottom 32. such parts being suitably fastened together by either tacks or adhesive or by both. I

(lo-aligned vertical orifices. 47 are formed in the foot 41 and the amplifier bottom 32 to register with a similar aperture formed in the said horizontal panel 22 to thereby provide a passage for the sound waves from the tone arm 12 into the interior of the amplifier shell. 7 y

In order to prevent the sound waves from the tone arm impinging against the inner surface of the top 31 of the shell, the inner surface 49 of the end closure 36 is curved upwardly and inwardly so that it merges into the inner surface of the top 31- and forms a throat 51 which progressively increases in. cross sectional area. If desired, the edges of the orifice 47 in the amplifier shell bottnm and the supporting foot 41 may be curved or chamfered to render the rate or increase in cross sectional area of the throat 51 more gradual. The sound waves are thus effectively directed into the shell, the change in the direction of travel from substantially vertical to substantially horizontal being gradual.

The sound passage provided by the amplifier shell gradually increases in cross sectional area from its inner end throughout its length and is entirely devoid of abrupt or acute bends so that a clear and highly satisfactory tonal effect is assured.

The amplifier shell is supported in its operative position within the compartment 29 by the horizontal panel 22 extending beneath the overhanging portion 21 of the vertical partition wall 17, the screws 4C3 holding the foot 4.1 to said panel. The outer end of the shell may also be supported by its lower front edge resting upon a ledge 53 defining the lower edge of the sound outlet opening 35 in the front of the cabinet. A screen or shutter 54 which may be adjustable or otherwise may be fitted over the sound outlet opening 35 in accordance with the usual practice.

It will be evident that the top let of the cabinet is applied to the upstanding sides or walls thereof after the amplifier shell has been applied within its compartment 29.

The talking machine motor 56 indicated by broken lines in Figure 2 may be attached to the underside of the deck 16 and enclosed within a compartment 57 formed beneath said deck 16 by a second horizontal board or panel 58. The. numeral 59 indicates a door affording access to cupboard 61 which may be equipped with racks, shelves or the like for the reception of talking machine records.

Having now described our invention what we claim as new and desire to secure by Letters Patent is 1. A sound-reproducing machine, comprising a cabinet having within it an amplifier compartment and a record car ier and tone arm compartment, said cabinet embodying connected front, rear, side and top walls, the first of which is provided with a sound-outlet opening; a tone arm in the second compartment; and an amplifier unit mounted in the fist compartment and embodying top, bottom and upstanding side walls conjointly forming a relatively-narrow, straight inner portion which extends laterally within the compartment adjacent the rear wall of the cabinet, a flared outer portion the side walls of which diverge to the sound-outlet opening and are connected to said straight inner portion by an intermediate bend, and an inner end portion which is provided at its bottom with an inlet orifice for connection with the delivery end of the tone arm the bottom wall of the amplifier being substantially horizontal from its inner end to said intermediate bend, from which point said bottom wall slopes downwardly and forwardly to said sound-outlet opening, and the side walls of the amplifier being of progressively-increasing height from the intermediate bend to the soundoutlet opening.

2. A sound-reproducing machine, comprising a cabinethaving within it an amplifier compartment and a record carrier and tone arm compartment; a tone arm in the second compartment; and an amplifier unit mounted in the first compartment and embodying top, bottom and side walls conjointly forming a relatively-narrow, laterally-extending inner portion which is provided at its bottom with an inlet orifice for connection with the delivery end of the tone arm, an outer flared portion which extends forwardly from said inner portion to the mouth of the amplifier, and an intermediate bend connecting said inner and outer portions, the said inner portion overhanging thetone arm.

3. A sound-reproducing machine, comprising a cabinet embodying connected front, rear, side and top walls, the front wall having a sound-outlet opening, and one side wall having an access opening; a horizontal partition in the upper portion of the cabinet; a vertical partition disposed in the space between said horizontal partition and top wall and dividing such space into a record carrier and tone arm compartment and an amplifier compartment located at opposite sides of the vertical partition and communicating, respectively, with the access opening and the sound-outlet opening, said vertical partition extending diagonally inward from the front corner edge of the cabinet adjacent said access opening and then curving laterally toward that opening and having its inner end stepped so as to provide an overhang which is spaced above the horizontal partition; a tone arm arranged in the first-named compartment, horizontal and vertical panels closing the bottom and outer end of the overhang, the horizontal panel having an opening to register with the delivery end of the tone arm; and an amplifier unit in the second-named compartment separate and distinct from the walls thereof and having its inlet end in registration with said panel opening.

In testimony whereof we affix our signatures.

JOHN ROBERT OBRIEN.

W ILFRED REVELL. 

